System for reordering the fuel injection sequence to facilitate starting of an internal combustion engine

ABSTRACT

Disclosed is an auxiliary start control for a fuel injection equipped internal combustion engine system which reorders the fuel injection sequence during the engine&#39;&#39;s starting cycle to facilitate a cold start. The system redirects the injection signals to alternate fuel injection valves so that during the start attempt fuel is injected directly into open intake valve ports. The system is effective in facilitating the start of both hot and cold engines.

United States Patent Keranen 1 Dec. 2, 1975 [54] SYSTEM R REORDERING THE F 3,664,311 5/1972 Endo 123/37 EA INJECTION SEQUENCE T0 FACILITATE gonoet a1. ll2233/l279El/S:

, mor1 3 STARTING OF AN INTERNAL 3,734,067 5/1973 GlOCkGf et a1.. 123 /179 L COMBUSTION ENGINE 3,754,537 9/1973 Wcssel ct a1. 123/32 EA 75 inventor: Theodore w Keranen, Pontiac I 3,782,338 1/1974 Hayashi ct all... 123/32 EA Mich 3,812,830 5/1974 Traisnel ,1 123/179 L 3,854,458 12/1974 Reddy 123/32 EA [73] Assignee: The Bendix Corporation, Southfield,

Mich. Primary ExaminerWende1l E. Burns Assistant Examiner.lames W. Cranson, Jr. [22] Flled' 1974 Attorney, Agent, or Firm-James R. Ignatowski [21] Appl. No.: 526,863

[57] ABSTRACT 52 us CL 123 9 123/32 123/179 Disclosed is an auxiliary start control for a fuel injec- 123/139 w tion equipped internal combustion engine system 51 Int. Cl. F02M 51/00; F02M 39/00 which reordersthe fuel injection Sequence during the [58] Field f Search 123/179 L, 179 G, 32 EA engines starting cycle to facilitate a cold start. The system redirects the injection signals to alternate fuel 5 References Cited injection valves so that during the start attempt fuel is UNITED STATES PATENTS injected directly into open intake valve ports. The system is effective in facilitating the start of both hot and 2,997,992 7/1961 Haefner et a1 123/32 EA cold engines, 3,623,460 11/1971 Kormaroff et a1... 123/32 3,646,915 3/1972 Rachel 123/179 G 23 Claims, 6 Drawing Figures SYSTEM FOR REORDERING THE FUEL INJECTION SEQUENCE TO FACILITATE STARTING OF AN INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electrical fuel injection control systems for internal combustion engine and, more particularly, to a control system for controlling the sequence of fuel injection relative to the opening of the engines intake valves during a start attempt.

2. Description of the Prior Art Conventional electrical fuel injection (EFI) systems are generally designed to provide fuel injection signals correlated with the rotatation of the engine and usually synchronous with the opening of the intake valve. In many current EFI systems, such as disclosed by Wessel et al, U.S. Pat. No. 3,754,537 and many others, the fuel injectors are fired in groups of two or more in advance of the opening of any intake valve to the group. During hot engine operation the fuel is vaporized in the closed intake port by the hot valves and the walls of the intake port. However, when the engine is cold, the injected fuel condenses on the cold walls of the intake port and intake valve significantly reducing the ratio of the fuelair mixture making starting of the engine difficult, if not impossible. In the early development of fuelinjection systems, this problem was overcome by injecting additional fuel in the vicinity of the intake port to compensate for the amount of fuel condensed on the cold surfaces, as disclosed by Haefner et al., U.S. Pat. No. 2,997,992. Various types of fuel enrichment systems providing extra fuel to facilitate cold starting have subsequently been developed which precisely control the amount of additional fuel injected to prevent flooding of the engine. One such system is disclosed by Omori, U.S. Pat. No. 3,680,532. An alternate approach directed to EFI systems using individual injection means rather than group injection suggested by Endo, U.S. Pat. No. 3,664,311 which teaches that cold starting can be facilitated by injecting the fuel directly into the cylinder when the intake ports are open. To accomplish this, Endo discloses a means for electronically delaying the injection signal as a function of both engine speed and engine temperature so that during the cold start at-' tempt the commencement of fuel injection is coincident with the opening of the intake valve. When the engine reaches normal operating temperatures and speed, the commencement of fuel injection precedes the opening of the intake valve for the same reasons discussed relative to group injection systems. Although the Endo technique is disclosed relative to EFI systems using independently control injectors and may be applicable to EFI systems using group injection-methods, the method is relatively complex' and sophisticated for use in many commercial applications. It has been found that the same effect can be accomplished by reordering the injection sequence so that injection signal ordinarily energizing a first injector or group of injectors energizes an alternate injector or group of injectors so that the energized injectors inject fuel into the engine cylinders when the intake ports are open.

Reordering, as used herein, means redirecting the sequential signals generated by the electronic control unit from one injector valve to another so that each se-' quential signal will activate an injector valve different from the one it activates during the normal operation of the engine.

The object of the invention is a simple control to facilitate starting of an engine using individual or group injection methods by reordering the injection sequence providing for the injection of fuel into open intake ports of the engine during a start attempt. Another object of the invention is a control for reordering the injection sequence during a cold start. Another object of the invention is a simple control in the limiting case of a two group fuel injection fuel control system for reversing the injection sequence during a start attempt. These and other advantages will become apparent from a further reading of the detailed discussions hereafter.

SUMMARY OF THE INVENTION The invention is an auxiliary start control system for fuel injection equipped internal combustion engine operative to detect a cold start attempt and reorder the injection sequence to change the timing between the fuel injection and the opening of intake ports, so that during the start attempt" the fuel injection takes place when the input ports are open. The system comprises a means for generating a signal indicative of an attempt to start the engine and an electrical switching mechanism disposed between the control unit generating sequential electrical signals indicative of the engins fuel requirements and the respective fuel injection valves. The switching mechanism, in response to the start attempt signal, redirects the sequential electrical signals to alternate injector valves so that during the start attempt the signal is directed to an injector at a time when the intake port is open. By this reordering of the injection sequence, fuel is injected directly into open engine intake ports. With engine systems employing group fuel injection, the injection signal of each group is redirected to the injector group having open intake ports. In the limiting case of an engine having only a two group fuel injection system, the injection signals for the two groups are simply reversed. The auxiliary start control is effective for starting both hot and cold engine, but may be limited to just cold starts by controlling the generation of the start signal to engine temperatures below a predetermined value BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a chart showing the intake valve open periods for an eight cylinder engine as a function of the engines crankshaft angle;

FIG. 2 is a block diagram of the start control system for the engine system shown in FIG. 1;

FIG. 3 is a schematic of the start control;

FIG. 4 is aschematic showing an electromagnetic switch for reversing the injection sequence for a two group fuel injection system;

FIG. 5 is a schematic illustrating a solid state switch for'reordering the injection sequence for a four group fuel injection system;

FIG. 6 is a block diagram of an alternate embodiment providing injection signal reversal for a cold orwarm engine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A FIG. Ipictorially illustrates the operational cycle of a typical eight cylinder fuel injector equipped engine having a two group injection means. In particular, FIG.

l graphically depicts the commencement of fuel injection versus the intake valve open period plotted as a function of the crankshafts rotational position. The cylinder members 1 through 8 are shown to the left of the figure opposite an associated row and appear in the sequential order of ignition or spark plug firing. The cross hatched area in each row indicates the intake valve open period for each cylinder and the small circle following the cross hatched area indicates when the spark plug is fired. For the typical four cycle engine, the operational cycle is 720 or two revolutions of the crankshaft. In the example of FIG. 1 the cylinders are divided into two groups having sequential open intake valve periods and the firing order as shown. The first group comprises cylinders 7, 2, 1 and 8 and the second group comprises 4, 3, 6 and 5. It is recognized that this division is arbitrary and any other sequential cylinder groups could have been selected. The heavy vertical bars, one at approximately 120 encompassing cylinders 7, 2, 1 and 8, and the other at approximately 480 encompassing cylinders 4, 3, 6, and 5, indicate the ratational angles at which fuel injection for groups 1 and 2 respectively is commenced. From this chart it can be seen that if the electrical signal energizing the injector valves in group 1 was applied to injector valves in group 2 and vice versa, the fuel would be injected into six of the eight cylinders during the period when the intake valves were open. In accordance with the teachings of Endo, this should enhance the starting of a cold engine. This concept has been experimentally verified.

A block diagram of the preferred embodiment is illustrated in FIG. 2. The group injection trigger signals are generated by an electronic control unit 10 in response to inputs from a variety of sensors 14 and a sensor 12 generating a signal indicative of the engine's crank angle. This signal may be derived from the engines ignition system or any rotational member of the engine, as is well known in the art. The electronic control unit 10, in response to engine sensors 12 and 14, generates group injection signals having pulse durations indicative of the engines fuel requirements. The injection signals for one group of fuel injectors are output from the electronic control unit 10 to a signal reversing switch 16 on lead 18 while the injection signals for the other group of injectors are output to the signal reversing switch 16 on lead 20.

In the unactivated state the reversing switch 16 transmits the signals on lead 18 to Fuel Injector Group 1, block 22 on lead 24 and the signals on lead to Fuel Injector Group 2, block 26 on lead 28. In the activated state reversing switch 16 transmits the signals appearing on lead 18 to Fuel Injector Group 2, block 26 by means of lead 28, and the signals appearing on lead 20 to Fuel Injector Group 1, block 22 by means of lead 24. The reversing switch 16 is activated by a signal from the start control 30 generating a start condition signal indicative of a start attempt. The signal indicative of a start attempt, such as closing the starter relay switch 32, applies electrical power from a battery 34 or other source of electrical power to the start control 30. The start control further responds to a temperature signal generated by an engine temperature sensor which prohibits the start control from generating the start condition signal when the engines temperature is above a predeterminable value.

In operation, the operator indicates a start attempt by closing the starter relay switch 32 applying a start attempt signal in the form of battery power to the start control 30. The start control, in response to the signal generated by the engine termperature sensor 36, generates a start condition signal when the engines temperature is below the predetermined temperature. In the mean time the electronic control unit 10, in response to the inputs from the engine sensors, generates group injection pulses output to the signal reversing switch 16 on leads 18 and 20. The reversing switch 16, in response to the start condition signal, transmits the signals on lead 18 to the fuel injectors of Group 2, block 26, via lead 28 and the signals on lead 20 to the fuel injectors of Group 1, block 22, via lead 24. Termination of the start attempt signal by opening the starter relay switch 32 or a signal generated by the engine temperature sensor 36 indicative that the engines temperature is above the predetermined value terminates the start condition signal generated by the start control 30 and the reversing swtich l6 reverts to its unactivated state and the signals on lead 18 is transmitted to the fuel injectors in Group 1 and the signals on lead 20 are transmitted to the fuel injectors in Group 2 returning the timing between fuel injection and opening of the intake valves to their normal sequence. Although the basic concepts have been discussed with reference to an electronic control unit only generating two group injection signals, a person skilled in the art will recognize that the invention is also applicable to an electronic control unit generating three or more group injection signals.

FIG. 3 illustrates one possible embodiment of the start control 30. The engine temperature sensor 36, which may be a thermistor, transistor or any other type of temperature sensor, generates a signal indicative of the engines temperature. The temperature sensed may be the temperature of the engines block, the temperature of the coolant, or the temperature of the oil. The temperature signal is applied to one input terminal of an operational amplifier 38. The alternate input to the operational amplifier indicative of the start attempt is provided from the battery 34, the starter relay switch 32 and the potential divider circuit consisting of resistances 40 and 42. The values of resistances 40 and 42 are selected to provide at their junction A a fixed reference value indicative of a predetermined temperature. When the signal generated by the temperature sensor 36 is-below the value generated at the junction A of the divider circuit, the operational amplifier generates a start condition signal. When the temperature signal is above the predetermined value, the operational amplifier is blocked. It would be obvious to one skilled in the art that a capacitance, such as capacitance 44 (dashed lines) could be added to the start control which would maintain the generation of the start condition signal by the operational amplifier for a predetermined time after the starter relay switch 32 has been opened. This would continue the reordered injection for a predetermined time after the engine started insuring the start quality of the engine.

The signal reversing switch may be an electromechanical double-pole, double-throw relay switch as shown in FIG. 4, or a solid state switch performing the same function as shown in FIG. 5. Referring to FIG. 4, the signal reversing switch 16 comprises an electromagnetic coil 46 receiving the start condition signal from the start control 30. The electromagnetic coil 46 is adapted to control the position of switch contacts 48 and 50 electrically connected to leads l8 and 20 as shown. In the unactivated state of the coil, the switch contact 48 and 50 are biased by resilient means (not shown) to be in electrical contact with terminal 52 and 54 applying the signals appearing on leads 18 and 20 to leads 24 and 28 respectively. In response to a start condition signal, coil 46 is actuated and moves contacts 48 and 50 into electrical contact with terminals 56 and 58 applying the signals appearing on leads 18 and 20 to leads 28 and 24 respectively reversing the response of the fuel injectors in Group 1 and Group 2 to the generated group injection signals.

FIG. 5 illustrates a solid state embodiment of the reversing switch 16 for a four group injection system. The

solid state reversing switch comprises a plurality of AND gates as shown. AND gates 60, 64 68 and 72 are activated by a low signal on the input terminal having the small circle and a high signal on the alternate terminal. AND gates 62, 66, 70 and 74 are conventional AND gates and are actuated only when the signals on both terminals are high. The electronic control unit outputs the four sequential group injection signals on leads 76, 78, 80 and 82 respectively. Lead 76 is connected to the alternate input terminal on AND gate 60 and one input terminal on gate 74. Lead 78 is connected to the alternate input terminal on gate 64 and to one of the input terminals on gate 62. Likewise, leads 80 and 82 are connected to the alternate input terminals on gates 68 and 72 respectively and to an input terminal on gates 66 and 70. The start condition signal from the start control 30 is connected to the other terminals on each AND gate. It is assumed the group injection signals on leads 76 through 82 and the start condition signal are all high signals. The signal terms high" and low have the conventional electronic logic meanings. In the absence of a start attempt signal, the signal generated by the start control 30 is zero or low, therefore, gates 62, 66, 70 and 74 are blocked. However, gates 60, 64, 68 and 72 which require low signals at the input terminals with the small circles become active whenever a high signal appears on leads 76 through 82. In this state, the group injector signals on leads 76 through 82 are applied to the fuel injectors in Groups 1 through 4, blocks 84 through 90 respectively via leads 92 through 98 respectively. When the start control generates a high start condition signal, gates 60, 64, 68 and 72 are blocked and gates 62, 66, 70 and 74 become active whenever high group injection signals appear on leads 76 through 82. In this state the high group injector signals on leads 76 through 82 are applied to the fuel injectors in Groups 4, l, 2 and 3, respectively. In this manner the fuel injection for each group is delayed. Obviously, this concept may be extended to engines having independent signals for each injector valve, also other solid state devices such as a shift register may be used to perform the desired reordering of the response of the injector valves to the sequentially generated injection signals.

The preferred embodiment of the invention is shown reordering the group injector signals primarily to enhance cold starting, however, it is recognized that reordering of single group injector signals is also beneficial during warm or even hot start, therefore, it is possible to omit temperature responsive start control 30 and trigger the reversal switch 16 directly from starter relay switch as shown in FIG. 6. The elements of the system are the same as shown in FIG. 2 and no further explanation is required.

The illustrations and circuits shown and discussed with reference to the preferred embodiment are presente d for the purpose of understanding the invention and are not intended to limit the scope thereof. It is possible for a person skilled in the art to modify the circuits or adapt the system to internal combustion engines having more or less than the eight cylinders used in the example, or to electronic control units which generate more than two group injection signals or even systems having sequential signals for each individual valve without departing from the scope of the invention.

What is claimed is:

1. A system for enhancing the start of a fuel injection equipped internal combustion engine, said engine having a plurality of cylinders and an electronic control unit generating in synchronization with the rotation of the engine at least two sequential injection signals indicative of the engines fuel requirements, each cylinder having an associated intake valve and fuel injector valve, said intake valves periodically opening in synchronization with the rotation of the engine to admit a mixture of fuel and air into the cylinders and each in jector valve sequentially injecting fuel for each cylinder in response to one of said sequential injection signals wherein said injection signals are generated at a time relative to the opening of the associated intake valves to commence fuel injection for each cylinder prior to the opening of the associated intake valve, and wherein said engine further includes an electrically actuated starter to crank the engine to effect a start thereof comprising:

means for generating a start attempt signal indicative of an attempt to start the engine in response to the actuation of the starter; and

means electrically disposed between the electronic control unit and the fuel injector valves, for reordering, in response to said start attempt signal, the sequence in which the injector valves are actuated by the generated injection signals to commence fuel injection for each cylinder when the associated intake valve is open.

2. The system of claim 1 wherein the electronic control unit generates at least two sequential group injection signals for sequentially actuating predetermined groups of fuel injector valves, wherein each predetermined injector valve group comprise more than one fuel injector valve, said means for reordering comprises:

means receiving said sequential group injector signals for reordering the sequence in which the injector valve groups are actuated by the generated group injection signals to commence fuel injection for each injector valve group when at least one intake valve associated with the injector group is open.

3. The system of claim 2 wherein the electronic control unit includes a temperature sensor generating a signal indicative of the engine's temperature, said means for generating a signal indicative of a start attempt further includes means receiving said temperature signal for controlling the generation of said signal as a function of the engine's temperature.

4. The system of claim 2 wherein said means for generating a signal indicative of a start attempt further includes:

a sensor generating a signal indicative of the engines temperature; and

means receiving said temperature signal for controlling the generation of said start attempt signal as a function of the engines temperature.

5. The system of claim 3 wherein said means for controlling includes means for generating said start attempt signal only when the engines temperature is below a predetermined value.

6. The system of claim 5 wherein said means for controlling further includes means for generating said start attempt signal for a predetermined time after the actuation of the starter is terminated.

7. The system of claim 2 wherein the electronic control unit generates just two sequential group injection signals and said engine has only two injector valve groups, said means for reordering reverses the sequence in which the two injector groups are actuated by the sequential group injection signals.

8. The system of claim 7 wherein said means for reordering is an electromechanical relay having at least two mechanical switches actuated by an electromagnetic coil, said mechanical switches having an unactuated state providing electrical continuity respectively between the two sequentially generated group injection signals and the two injector valve groups, and and actuated state in which the electrical continuity between the sequentially generated group injection signals and the associated injector valve groups is reversed.

9. The system of claim 7 wherein said means for reordering is a solid state switch having a first state providing electrical continuity between the two sequentially generated group injection signals and the two injector valve groups wherein one group injection signal is communicated to one injector valve group and the other group injector signal is communicated to the other injector valve group, and said solid state switch switchable to a second state in response to said start attempt signal switching the electrical continuity between said two sequentially generated group injection signals to reverse the order in which the injector valve groups are actuated by the group injection signals.

10. In combination with an internal combustion engine having a plurality of cylinders and an intake valve associated with each cylinder which periodically opens to admit a combustable mixture of fuel and air into each cylinder, a sensor controlled electronic control unit generating signals indicative of the engines fuel requirements and at least one fuel injector valve associated with each cylinder sequentially injecting fuel in response to said injection signals, wherein the injection signals'are synchronized with the opening of each intake valve to commence fuel injection for each cylinder prior to the opening of the associated intake valve, and wherein the engine further includes an electrically actuated starter to crank the engine to effect the start, an improvement comprising:

means for generating a start attempt signal indicative of an attempt to start the engine by actuating the starter; and

means electrically disposed between the electronic control unit and the fuel injection valves and receiving said sequentially generated injection signals for changing, in response to said start attempt signal, the sequential order in which the fuel injector valves respond to the sequential injection signals to commence the fuel injection when the intake valve of the associated cylinder is open.

ll. The improvement of claim 10 wherein the electronic control unit generates sequential group injection signals sequentially actuating predetermined groups of fuel injector valves prior to the opening of the associated intake valves, wherein each group of injector valves comprise more than one fuel injector valve, and wherein one of said predetermined groups is responsive to one of said group injection signals, and the other predetermined groups are sequentially responsive to the other sequentially generated group injection signals in a predetermined sequence, said means for changing comprises:

means receiving said sequential group injector signals for changing the sequential order in which injector valve group responds to the sequential group injection signals to commence fuel injection by the group of injector valves when at least one intake valve associated with"the group is open.

12. The improvement of claim 11 wherein the electronic control unit includes a temperature sensor generating a signal indicative of the engines temperature, said means for generating a start attempt signal further includes means receiving said temperature signal for controlling the generation of said start attempt signal as a function of the engins temperature.

13. The system of claim 11 wherein said means for generatinga start attempt signal further includes:

a sensor generating a signal indicative of the engine s temperature; and

means receiving said temperature signal for controlling the generation of said start attempt signal as a function of the engines temperature.

14. The improvement of claim 13 wherein said means for controlling includes means for generating said start attempt signal only when the engines temperature is below a predetermined value.

15. The improvement of claim 14 wherein said means for controlling further includes means for generating said start attempt signal for a predetermined time after the actuation of the starter is terminated.

16. The improvement of claim 11 wherein the electronic control unit generates just two sequential group injection signals and said engine has only two injector valve groups, said means for changing the order of response, reverses the order of the response of the two injector groups to the two sequential group injection signals.

17. The improvement of claim 16 wherein said means for changing is an electromechanical relay having at least two switches actuated by an electromagnetic coil, said electrical switch having an unactuated state providing electrical continuity respectively between the two sequentially generated group injection signals and the two injector valve groups, and an actuated state in which the electrical continuty between the sequentially generated group injection signals and the associated injector valve groups is reversed.

18. The system of claim 16 wherein said means for changing is a solid state switch having a first state providing electrical continuity between the two sequentially generated group injection signals and the two injector valve groups wherein one group injection signal is communicated to one injector valve group, and the other group injection signal is communicated to the other injector valve group, and said solid state switch switchable to a second state in response to said start attempt signal switching the electrical continuity between said two sequentially generated group injection signals to reverse the order in which the injector valve groups are actuated by the group injection signals.

19. A method for enhancing the starting of an internal combustion engine having a plurality of cylinders and an electronic control unit generating in synchronization with the rotation of the engine at least two sequential injection signals indicative of the engines fuel requirements, each cylinder having an associated intake valve and fuel injector valve, said intake valves periodically opening in synchronization with the rotation of the engine to admit a mixture of fuel and air into the cylinders and each injector valve sequentially injecting fuel for each cylinder in response to one of said sequential injection signals wherein said injection signals are generated at a time relative to the opening of the associated intake valves to commence fuel injection for each cylinder prior to the opening of the associated intake valve, and wherein said engine further includes an electrically actuated starter to crank the engine to effect a start thereof comprising the steps of:

generating a start attempt signal in response to the actuation of the starter;

applying said start attempt signal to a switching means to change the sequential order in which the fuel injector valves actuated by the sequentially generated injection signals causing the fuel injection for each cylinder to commence when the associated intake valve is open.

20. The method of claim 19 wherein the electronic control unit generates sequential group injection signals for sequentially actuating predetermined groups of fuel injector valves prior to the opening of the associated intake valves wherein each injector valve group comprises more than one injector valve, and wherein one of said predetermined groups of injector valves is actuated by one of said group injector signals and the other groups are actuated by the other group injection signals in a predetermined sequence, said step for applying comprises applying said start attempt signal to a switch means for changing the sequential order in which the injector valve groups are actuated by the sequentially generated group signals to commence fuel injection for the group when at least one intake valve associated with the group is open.

21. The method of claim 20 wherein the step of generating a start attempt signal includes:

generating a temperature signal indicative of the engines temperature;

generating a start signal indicative of actuation of the starter; and

generating said start attempt signal in response to said start signal when said temperature signal is indicative of an engine temperature below a predetermined value.

22. The method of claim 21 wherein said step of generating said start attempt signal further includes the step of temporarily storing said start signal to continue the generation of said start attempt signal for a predeterminable time after the actuation of the starter has been terminated.

23. The method of claim 20 wherein said electronic control unit generates just two sequential group injection signals and said engine has only two groups f0 fuel injector valves, said step of applying comprises applying said start attempt signal to a switch means to reverse the order in which said two groups of injector valves are actuated by the two sequential group signals. 

1. A system for enhancing the start of a fuel injection equipped internal combustion engine, said engine having a plurality of cylinders and an electronic control unit generating in synchronization with the rotation of the engine at least two sequential injection signals indicative of the engine''s fuel requirements, each cylinder having an associated intake valve and fuel injector valve, said intake valvEs periodically opening in synchronization with the rotation of the engine to admit a mixture of fuel and air into the cylinders and each injector valve sequentially injecting fuel for each cylinder in response to one of said sequential injection signals wherein said injection signals are generated at a time relative to the opening of the associated intake valves to commence fuel injection for each cylinder prior to the opening of the associated intake valve, and wherein said engine further includes an electrically actuated starter to crank the engine to effect a start thereof comprising: means for generating a start attempt signal indicative of an attempt to start the engine in response to the actuation of the starter; and means electrically disposed between the electronic control unit and the fuel injector valves, for reordering, in response to said start attempt signal, the sequence in which the injector valves are actuated by the generated injection signals to commence fuel injection for each cylinder when the associated intake valve is open.
 2. The system of claim 1 wherein the electronic control unit generates at least two sequential group injection signals for sequentially actuating predetermined groups of fuel injector valves, wherein each predetermined injector valve group comprise more than one fuel injector valve, said means for reordering comprises: means receiving said sequential group injector signals for reordering the sequence in which the injector valve groups are actuated by the generated group injection signals to commence fuel injection for each injector valve group when at least one intake valve associated with the injector group is open.
 3. The system of claim 2 wherein the electronic control unit includes a temperature sensor generating a signal indicative of the engine''s temperature, said means for generating a signal indicative of a start attempt further includes means receiving said temperature signal for controlling the generation of said signal as a function of the engine''s temperature.
 4. The system of claim 2 wherein said means for generating a signal indicative of a start attempt further includes: a sensor generating a signal indicative of the engine''s temperature; and means receiving said temperature signal for controlling the generation of said start attempt signal as a function of the engine''s temperature.
 5. The system of claim 3 wherein said means for controlling includes means for generating said start attempt signal only when the engine''s temperature is below a predetermined value.
 6. The system of claim 5 wherein said means for controlling further includes means for generating said start attempt signal for a predetermined time after the actuation of the starter is terminated.
 7. The system of claim 2 wherein the electronic control unit generates just two sequential group injection signals and said engine has only two injector valve groups, said means for reordering reverses the sequence in which the two injector groups are actuated by the sequential group injection signals.
 8. The system of claim 7 wherein said means for reordering is an electromechanical relay having at least two mechanical switches actuated by an electromagnetic coil, said mechanical switches having an unactuated state providing electrical continuity respectively between the two sequentially generated group injection signals and the two injector valve groups, and and actuated state in which the electrical continuity between the sequentially generated group injection signals and the associated injector valve groups is reversed.
 9. The system of claim 7 wherein said means for reordering is a solid state switch having a first state providing electrical continuity between the two sequentially generated group injection signals and the two injector valve groups wherein one group injection signal is communicated to one injector valve group and the other group injector signal is communicated to the other injector valvE group, and said solid state switch switchable to a second state in response to said start attempt signal switching the electrical continuity between said two sequentially generated group injection signals to reverse the order in which the injector valve groups are actuated by the group injection signals.
 10. In combination with an internal combustion engine having a plurality of cylinders and an intake valve associated with each cylinder which periodically opens to admit a combustable mixture of fuel and air into each cylinder, a sensor controlled electronic control unit generating signals indicative of the engine''s fuel requirements and at least one fuel injector valve associated with each cylinder sequentially injecting fuel in response to said injection signals, wherein the injection signals are synchronized with the opening of each intake valve to commence fuel injection for each cylinder prior to the opening of the associated intake valve, and wherein the engine further includes an electrically actuated starter to crank the engine to effect the start, an improvement comprising: means for generating a start attempt signal indicative of an attempt to start the engine by actuating the starter; and means electrically disposed between the electronic control unit and the fuel injection valves and receiving said sequentially generated injection signals for changing, in response to said start attempt signal, the sequential order in which the fuel injector valves respond to the sequential injection signals to commence the fuel injection when the intake valve of the associated cylinder is open.
 11. The improvement of claim 10 wherein the electronic control unit generates sequential group injection signals sequentially actuating predetermined groups of fuel injector valves prior to the opening of the associated intake valves, wherein each group of injector valves comprise more than one fuel injector valve, and wherein one of said predetermined groups is responsive to one of said group injection signals, and the other predetermined groups are sequentially responsive to the other sequentially generated group injection signals in a predetermined sequence, said means for changing comprises: means receiving said sequential group injector signals for changing the sequential order in which injector valve group responds to the sequential group injection signals to commence fuel injection by the group of injector valves when at least one intake valve associated with the group is open.
 12. The improvement of claim 11 wherein the electronic control unit includes a temperature sensor generating a signal indicative of the engine''s temperature, said means for generating a start attempt signal further includes means receiving said temperature signal for controlling the generation of said start attempt signal as a function of the engin''s temperature.
 13. The system of claim 11 wherein said means for generating a start attempt signal further includes: a sensor generating a signal indicative of the engine''s temperature; and means receiving said temperature signal for controlling the generation of said start attempt signal as a function of the engine''s temperature.
 14. The improvement of claim 13 wherein said means for controlling includes means for generating said start attempt signal only when the engine''s temperature is below a predetermined value.
 15. The improvement of claim 14 wherein said means for controlling further includes means for generating said start attempt signal for a predetermined time after the actuation of the starter is terminated.
 16. The improvement of claim 11 wherein the electronic control unit generates just two sequential group injection signals and said engine has only two injector valve groups, said means for changing the order of response, reverses the order of the response of the two injector groups to the two sequential group injection signals.
 17. The improvement of claim 16 wherein said means for changiNg is an electromechanical relay having at least two switches actuated by an electromagnetic coil, said electrical switch having an unactuated state providing electrical continuity respectively between the two sequentially generated group injection signals and the two injector valve groups, and an actuated state in which the electrical continuty between the sequentially generated group injection signals and the associated injector valve groups is reversed.
 18. The system of claim 16 wherein said means for changing is a solid state switch having a first state providing electrical continuity between the two sequentially generated group injection signals and the two injector valve groups wherein one group injection signal is communicated to one injector valve group, and the other group injection signal is communicated to the other injector valve group, and said solid state switch switchable to a second state in response to said start attempt signal switching the electrical continuity between said two sequentially generated group injection signals to reverse the order in which the injector valve groups are actuated by the group injection signals.
 19. A method for enhancing the starting of an internal combustion engine having a plurality of cylinders and an electronic control unit generating in synchronization with the rotation of the engine at least two sequential injection signals indicative of the engine''s fuel requirements, each cylinder having an associated intake valve and fuel injector valve, said intake valves periodically opening in synchronization with the rotation of the engine to admit a mixture of fuel and air into the cylinders and each injector valve sequentially injecting fuel for each cylinder in response to one of said sequential injection signals wherein said injection signals are generated at a time relative to the opening of the associated intake valves to commence fuel injection for each cylinder prior to the opening of the associated intake valve, and wherein said engine further includes an electrically actuated starter to crank the engine to effect a start thereof comprising the steps of: generating a start attempt signal in response to the actuation of the starter; applying said start attempt signal to a switching means to change the sequential order in which the fuel injector valves actuated by the sequentially generated injection signals causing the fuel injection for each cylinder to commence when the associated intake valve is open.
 20. The method of claim 19 wherein the electronic control unit generates sequential group injection signals for sequentially actuating predetermined groups of fuel injector valves prior to the opening of the associated intake valves wherein each injector valve group comprises more than one injector valve, and wherein one of said predetermined groups of injector valves is actuated by one of said group injector signals and the other groups are actuated by the other group injection signals in a predetermined sequence, said step for applying comprises applying said start attempt signal to a switch means for changing the sequential order in which the injector valve groups are actuated by the sequentially generated group signals to commence fuel injection for the group when at least one intake valve associated with the group is open.
 21. The method of claim 20 wherein the step of generating a start attempt signal includes: generating a temperature signal indicative of the engine''s temperature; generating a start signal indicative of actuation of the starter; and generating said start attempt signal in response to said start signal when said temperature signal is indicative of an engine temperature below a predetermined value.
 22. The method of claim 21 wherein said step of generating said start attempt signal further includes the step of temporarily storing said start signal to continue the generation of said start attempt signal for a predeterminable time after the actuation of the stArter has been terminated.
 23. The method of claim 20 wherein said electronic control unit generates just two sequential group injection signals and said engine has only two groups fo fuel injector valves, said step of applying comprises applying said start attempt signal to a switch means to reverse the order in which said two groups of injector valves are actuated by the two sequential group signals. 